四川东北区域冬小麦水分生产函数模型初探

A Preliminary Study on the Water Production Function Model of Winter Wheat in Northeast Sichuan

作物水分生产函数对灌溉工程的规划设计和水资源的合理使用都具有重大作用。本文基于四川省东北区域的气象观测数据,明确了适合该区域的最优人工智能蒸散模型,并且进一步基于实际蒸散量和冬小麦实际产量,建立和评估了全生育期水分生产函数模型。结果表明:1) 当温度、湿度、风速、日照气象条件都具备时,逐步线性回归(SLR)、回归树(RT)、支持向量机(SVM)、广义神经模型(GRNN)都能够较好地模拟冬小麦产区的参考作物蒸散量,其中GRNN模型是最优方法;2) 在不同地区GRNN模型计算的蒸散量与冬小麦产量关系的拟合精度存在明显差异。绵阳地区冬小麦产量随着蒸散量的增加呈下降趋势,而在巴中地区冬小麦产量随着蒸散量的增加表现为先增加后减小。3) 对水分生产函数精度的验证表明在遂宁地区线性模型模拟的产量大部分偏小,而抛物线模型模拟的产量偏大;绵阳地区线性模型和抛物线模型整体而言模拟的产量都偏小;巴中地区抛物型模型对产量的模拟精度最好。

Crop water production function plays an important role in the planning and design of irrigation projects and the rational use of water resources. Based on the meteorological observation data of northeast Sichuan Province and the actual yield of winter wheat, the optimal artificial intelligence evapotranspiration model suitable for the region is clarified. And further based on the actual evapotranspiration and the actual yield of winter wheat, water production function model in the whole growth period are established and evaluated. The results show that: 1) When temperature, humidity, wind speed, and sunshine meteorological conditions are available, stepwise linear regression (SLR), regression tree (RT), support vector machine (SVM), and generalized neural model (GRNN) can better simulate the reference crop evapotranspiration in winter wheat producing areas, of which GRNN model is the optimal method;2) There were obvious differences in the simulation precision of the evapotranspiration calculated by the GRNN model and the yield relationship of winter wheat in different regions. The yield of winter wheat in Mianyang region showed a downward trend with the increase of evapotranspiration, while the yield of winter wheat in Bazhong region increased first and then decreased with the increase of evapotranspiration. 3) The verification of the precision of water production function shows that in the Suining region, the winter wheat’ yield simulated by the linear model is mostly small, while the winter wheat’ yield simulated by the parabolic model is larger. On the whole, the winter wheat’ yield simulated by linear and parabolic model are both smaller in the Mianyang region. The parabolic model in Bazhong area has the best simulation accuracy for the yield of winter wheat.